CVE-2026-86250

A flaw was found in h3. This vulnerability allows a remote attacker to send a specially crafted cookie header with an excessively large chunk count. This action triggers an inefficient cleanup process within the setChunkedCookie and deleteChunkedCookie functions, consuming significant server...

Duplicate Advisory: H3: Unbounded Chunked Cookie Count in Session Cleanup Loop may Lead to Denial of Service

Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-q5pr-72pq-83v3. This link is maintained to preserve external references. Original Description h3 versions before 2.0.1-rc.18 fail to validate the chunk count parsed from user-controlled cookie values in...

CVE-2026-86250 h3 before 2.0.1-rc.18 Denial of Service via Unbounded Chunked Cookie

h3 versions before 2.0.1-rc.18 fail to validate the chunk count parsed from user-controlled cookie values in setChunkedCookie and deleteChunkedCookie functions. Attackers can send a crafted cookie header with an extremely large chunk count to trigger an On² cleanup loop that hangs the server...

PT-2026-105508

Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-q5pr-72pq-83v3. This link is maintained to preserve external references. Original Description h3 versions before 2.0.1-rc.18 fail to validate the chunk count parsed from user-controlled cookie values in...

CVE-2026-86250: Uncontrolled Resource Consumption

h3 versions before 2.0.1-rc.18 fail to validate the chunk count parsed from user-controlled cookie values in setChunkedCookie and deleteChunkedCookie functions. Attackers can send a crafted cookie header with an extremely large chunk count to trigger an On² cleanup loop that hangs the server...